VISUAL LOCALIZATION OF THE HORIZONTAL AS A FUNCTION OF BODY TILT UP TO = 90 DEGREES FROM GRAVITATIONAL VERTICAL,
Abstract
The visual horizontal was determined for three sophisticated subjects tilted laterally in 10 degrees intervals within =90 degrees from gravitational vertical. The task had adequate intratest reliability, but there were considerable interest and intrasubject quantitative variations. Visual localization as a function of body tilt, however, was qualitatively similar among all subjects and among the thirteen test sessions of each subject. Around upright there was a range (totaling 20 - 40 degrees on the average) of body positions in which the deviation was not significant from that of upright. Inclinations beyond this range caused the E-phenomenon to appear and increase bilaterally up to a maximum of about the 40 - 50 degrees position; with further inclination the deviation reversed direction and passed through the position (60 - 80 degrees) of zero deviation to grow as the A-phenomenon. Responses were bilaterally symmetrical in certain respects for each of the subjects. The variable error among all subjects followed a similar (curvilinear) function of body attitude. Repetition of test without immediate knowledge of results did not as a rule end in reduction of errors. (Author)
Document Details
- Document Type
- Technical Report
- Publication Date
- Aug 03, 1965
- Accession Number
- AD0625266
Entities
People
- Alfred R. Fregly
- Ashton Graybiel
- Earl F. Miller Ii.
- Gert Van Den Brink
Organizations
- Naval Aerospace Medical Institute